Marie Louise Marcadet née Baptiste (3 December 1758 – 28 February 1804) was a Swedish opera singer and a dramatic stage actress of French origin.

She made her debut at the Royal Swedish Opera in Bollhuset in the opéra bouffon Les deux avares by Grétry in the 1777–78 season, and was later the same year acclaimed in Lucile by the same composer.

On the occasion of her marriage, she was given the opportunity to stage her own production as a benefit performance, which was somewhat controversial and criticized by Gustaf Johan Ehrensvärd, who noted as criticism toward the opera manager Barnekow, that she: "acted as a director of the performance, which he should have done, disposed of the loges, auctioned them off, so that prime minister riksråd Ulric Scheffer lost his loge for not being the highest bidder... it was given to a cook and a chancellor.

The financial arrangements and employment conditions at the royal theater illustrate that Marie Louise Marcadet and Fredrica Löf was given the highest position of all women actors there.

She was highly respected as a professional artist, and was referred to as an example of the importance of education by Carl von Fersen in his work Operans och svenska spektaklets förbättrande (1780).

The critics appreciated that her hard French accent gave her speech power and energy, and she was admired for the impression of passionate strength she eluded.

She played Henriette in Les deux avares (season 1777–78), Arséne in the opera La belle Arsène by Monsigny (with Elisabeth Olin and Christoffer Christian Karsten) and Iphigenie in Iphigénie en Aulide by Gluck (with Carl Stenborg), 1779–80, Cybèle in Atys by Piccinni (with Carl Stenborg and Kristofer Kristian Karsten), 1784–85, Hermione in Andromaque by Grétry (with Franziska Stading), Cecilia av Eka in Gustaf Wasa by Johann Gottlieb Naumann (with Carl Stenborg, Kristofer Kristian Karsten and Caroline Halle-Müller), 1785–86, Ramfrid in Folke Birgersson till Ringstad by Gustav III (with Kristofer Kristian Karsten and Inga Åberg), 1792–93, and Minerva in Alcides inträde i världen (The arrival of Alcide in the world) by Haeffner, 1793–94.